1. Field of the Invention
This invention relates to a laser recording method and a laser recording apparatus or more particularly to a laser recording method and a laser recording apparatus in which the original is scanned by a solid state image sensor to convert the data on the original into time sequential picture signals and the picture is recorded on the light sensitive recording medium by controlling the laser beam by the picture signals.
2. Description of the Prior Art
Various kinds of laser recording methods and apparatuses have been offered and practiced in recent years, in which lines are scanned using a laser that has been modulated according to the data to be recorded on a light sensitive recording medium such as a photoconductive light sensitive body to form an electrostatic latent image which conforms to the data to be recorded and which then utilize this latent image.
Among these laser recording methods and laser recording apparatus, the system in which laser recording is made while scanning and reading out the original to be recorded is offered as an effective system.
In this system, since a recording is made every time a line of the original is scanned, it is simple in construction and highly economical compared with the apparatus in which the original is read out in advance, the read-out signals are all memorized, and then the signals are read out from the memory.
In these conventional methods and apparatus the line reading and scanning of the original has been controlled according to the detection of the recording starting position and the recording ending position of the laser beam.
In making a laser beam recording, however, although the polygonal mirror used in the scanning of laser beam performs scanning while each mirror surface is moving through a position facing the laser light source, the actual scanning time available for recording is only 60% of the scanning time of each surface.
One reason for this is that the laser beam incident upon the polygonal mirror is a spot having a predetermined area, and the recording is made while the entire spot is incident upon the mirror surface.
Attempts to increase each scanning time by increasing the number of revolutions of the polygonal mirror are not always successful because there is a limit in the response speed of the solid state image sensor (normally a CCD) used ordinarily in line reading of the original.